A TAF4 coactivator function for E proteins that involves enhanced TFIID binding
- 1Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA;
- 2Laboratory Medicine, University of California at San Francisco School of Medicine, San Francisco, California 94143, USA
Abstract
The multisubunit TFIID plays a direct role in transcription initiation by binding to core promoter elements and directing preinitiation complex assembly. Although TFIID may also function as a coactivator through direct interactions with promoter-bound activators, mechanistic aspects of this poorly defined function remain unclear. Here, biochemical studies show a direct TFIID–E-protein interaction that (1) is mediated through interaction of a novel E-protein activation domain (activation domain 3 [AD3]) with the TAF homology (TAFH) domain of TAF4, (2) is critical for activation of a natural target gene by an E protein, and (3) mechanistically acts by enhancing TFIID binding to the core promoter. Complementary assays establish a gene-specific role for the TAFH domain in TFIID recruitment and activation of a large subset of genes in vivo. These results firmly establish TAF4 as a bona fide E-protein coactivator as well as a mechanism involving facilitated TFIID binding through direct interaction with an E-protein activation domain.
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Footnotes
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↵3 Corresponding author
E-mail roeder{at}mail.rockefeller.edu
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Supplemental material is available for this article.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.216192.113.
- Received February 17, 2013.
- Accepted June 12, 2013.
- Copyright © 2013 by Cold Spring Harbor Laboratory Press